[Gromov [1]}]
Let \(\langle M_1, d_1 \rangle \)  and \(\langle M_2, d_2 \rangle \)  be metric spaces, and let \(A,B,C\)  be non-negative integers with \(A\ge 1\) .
Then a function \(f:M_1\rightarrow M_2\)  is called an \((A,B,C)\) -quasi-isometry if the following two properties are satisfied:
